Semaphore-signal.



L. A. HAWKINS.

SEMAPHORE SIGNAL.

APPLICATION FILED APR. 6, 1910.

1,073,680, Patented Sept. 23, 1913.

Witnesses: Inventor Laurence .71. Hawkins, y MKQQ His fittorney.

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TA PATENT OFFICE.

LAURENCE A. HAWKINS, 0F SCHENECIADY, NEW YORK, ASSIGNOR, BY MESNE AS- SIGNMENTS, TO THE UNION SWITCH AND SIGNAL COMPANY, A CORPORATION OF PENNSYLVANIA.

SEMAPHORE-SIGNAL.

0 all whom it may concern:

Be it known that I, Lmuncucn A. Haw- KINS, a citizen of the United States, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Semaphorefiignals, of which the following is a specification.

My invention relates to semaphore signals of the type in which an electric motor is permanently geared to the semaphore arm, and is driven backward by the arm when the arm falls by gravity from clear to stop position.

It has been the practice heretofore in connection with such a mechanism to short-circuit the motor to cause it to act as a braking generator to retard the motion of the arm when the arm is falling by gravity.

My invention in one aspect consists in providing means for short-circuiting the motor momentarily only, so that the arm falls freely through the greater portion of its movement, but is retarded by the motor at the proper time. In the case of a twoposition arm, the motor, in accordance with my invention, is short-circuited just before reaching the stop position so as to cushion the fall of the arm. In a three-position nal, the motor is short-circuited also just before the arm reaches caution position so that it may stop at that position without shock.

In another aspect, my invention consists in cutting off the battery from the motor during the time the motor is short-circuited, so that in case the track relay should pick up while the signal is falling by gravity the battery would not be short-cireuited.

My invention will best be understood by reference to the accompanying drawing, in which- Figure 1 shows diagrammatically the connections of the control circuits for the motor arranged in accordance with my invention, the arrow indicating the direction of normal train movement, and Fig. 2 is a diagrammatic View of the signal mechanism.

In the drawings, A represents an electric motor which is permanently geared to the three-position semaphore arm B.

C represents a brake magnet which, when energized, applies a brake on the motor shaft to hold the semaphore arm at clear position.

Specification of Letters Patent.

Application filed April 6, 1910.

Patented Sept. 23, 191.3.

Serial No. 553,812.

Z), Z) and b represent contacts on the semaphore shaft.

I) represents a track relay controlling the. caution position of the signal, and E the line relay controlling the clear position.

F is a battery for supplying current to the motor.

G is a movable contact, normally in engagement with the stationary contact but adapted to be moved momentarily into engagement with another contact y by means of pins 71. and it (shown in Fig. 2) on the semaphore shaft.

The operation is as follows: When the block at which the semaphore is placed is clear the track relay 1) closes its contacts, closing a circuit through contact Z), motor A, contacts G and r to battery. The motor drives the signal to caution position. Just before caution position is reached, contact I) connects the brake coil C in shunt to contact 6 so that when the latter contact opens as caution position is reached, the brake magnet is thrown into series with the motor. This magnet is wound so as to take practically all of the voltage of the battery so that the motor is decnergized and the brake applied. hen line relay 1" is energized and closes its contacts, a circuit is closed through contact If, short-circuiting brake coil C so as to release the brake and starting the motor again. Before clear position is reached, contact 7) throws brake coil G into shunt with contact If so that when the latter contact opens at clear position the motor is deenergized and the brake applied.

When the line relay E is deenergized the semaphore arm is returned to stop position by gravity and falls freely until pin 7L engages contact G and presses it into engagement with contact g At this instant the motor is short-circuitcd and acts as a braking generator to retard the arm quickly. If contact relay D is still energized, the brake is applied as soon as caution position is reached and contact Z) closes the circuit of the brake coil. If, on the other hand, track relay D is also deenergized, the movement of the arm toward stop position continues. The arm again falls freely since pin h" releases contact G just before caution position is reached, and it continues to fall freely until it has nearly reached stop position when pin IL moves contact G again into engagement with contact 9 The motor again brakes the arm and slows it down so that when pin it releases contact G- ust before stop position is reached as shownin Fig. 2, I

the semaphore arm drops gently against its stop;

lVith the arrangement described, it will be seen that the arm drops freely and quickly except for the momentary retardation just before reaching caution and stop positions.

It will further be noted that when the motor A-is short-circuited by contacts G and g, the circuit of the battery P is opened at con tact .9 so that if the track or line relay should close its contacts while the motor is shortcircuited, the battery would. not be short circuited, since it would not be connected to the motor until after the contact G has left the contact 9 and returned to its normal position. While the signal is being driven from stop to caution and clear positions by the motor, the pins 72/ and ill produce no effeet on the motor circuit but simply press contact G more firmly against contact 9 as they pass.

I do not desire to limit myself to the particular construction and arrangement of parts shown and described but aim, in the appended claims, to cover all modifications which are within the scope of my invention.

What I claim as new and desire to secure by Letters Patent of the United States, is,

1. In combination with a three-position semaphore arm biased to stop position, an

electric motor for driving said arm to cantion and clear positions, gearing perma-- nently connecting the motor to the arm, whereby the motor is driven backward when the arm moves toward stop position by gravity, means for holding the arm at caution and clear positions, normally open contacts connected to the motor terminals, and means actuated by the arm for momentarily closing said contacts just before reaching cau- Copies of this patent may be obtained for time position when moving from clear to caution and again just before reaching stop position when moving from caution to stop.

2. In combination with a three-position semaphore arm biased to stop position, an electric motor for driving said arm to caution and clear positions, a source of current for the motor, gearing permanently connecting said motor to said arm, whereby said motor is driven backward when said arm moves toward stop position by gravity, means for holding said arm at caution and clear positions, normally open contacts connected to the motor terminals, normally closed contacts included in the connection from the motor to its source of current, and means actuated by the semaphore arm for momentarily closing the first mentioned con? tacts and opening the last mentioned contacts just before the arm reaches caution and stop positions in moving toward stop position.

3. In combination, a railway signal biased to danger position, an electric motor for moving it to caution and clear positions and operatively connected with the signal to move therewith while the latter is returning toward danger position, electrically controlled braking means for checking said return movement of the signal, and a circuit controller mechanically actuated by the signal for throwing said braking means into op eration during a portion of said return movement from clear position to caution position, and again during a portion of said return movement from caution position to danger position.

In witness whereof, I have hereunto set my hand this 4th day of April, 1910.

LAURENCE A. HAVVKI NS.

Witnesses:

BENJAMIN B. HULL, HELEN Onronn.

five cents each, by addressing the Commissioner of 'Patents, Washington, D. C. 

